This invention pertains to silicone resins having the general formula (R1SiO3/2)x(HSiO3/2)y where R1 is an alkyl group having 8 to 24 carbon atoms. The resins are used to form porous thin films on semiconductor devices.
Semiconductor devices often have one or more arrays of patterned interconnect levels that serve to electrically couple the individual circuit elements forming an integrated circuit (IC). The interconnect levels are typically separated by an insulating or dielectric coating. The coatings may be formed by chemical vapor deposition or by spin-on techniques. For example, U.S. Pat. No. 4,756,977 discloses the use of hydrogen silsesquioxane resins to form coatings on electronic devices.
As the size of the circuit elements and the spaces between such elements continues to decrease, there is a need for insulating materials that have a lower dielectric constant. In particular, materials that can provide a dielectric constant below 3 are desirable. One means for producing coatings that have a dielectric constant below 3 is to use spin-on materials that are silicon based and that when cured produce pores in the film.
Silicon containing spin-on materials have been described in U.S. Pat. Nos. 5,010,159 to Bank et al., U.S. Pat. No. 6,022,814 to Mikoshiba et al., and U.S. Pat. Nos. 6,143,855 and 6,177,199 to Hacker et al.
It has now been found that resins having the formula (R1SiO3/2)x(HSiO3/2)y where R1 is an alkyl group having 8 to 24 carbon atoms can be used to produce coatings on electronic devices, in particular semiconductor devices. These resins can be used to produce films having a dielectric constant of 1.5 to 2.3.
This invention pertains to silicone resins having the general formula (R1SiO3/2)x(HSiO3/2)y where R1 is an alkyl group having 8 to 24 carbon atoms. The resins can be used to form porous thin films on semiconductor devices by applying the resin onto a semiconductor device and heating the resin to a temperature sufficient to cure the resin and produce the porous coating. These coatings produced herein have a dielectric constant of 1.5 to 2.3.